Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Sandra M. Granquist (1, 2)
Starfsvettvangur / Affiliations: 1. Marine and Freshwater Research Institute, Hafnarfjörður, Iceland. 2. The Icelandic Seal Center, Hvammstangi, Iceland
Kynnir / Presenter: Sandra M. Granquist
Monitoring pinniped abundance is crucial to detect fluctuations in population sizes and a foundation to inform seal management. In this presentation, analysis of trends in the Icelandic harbour seal (Phoca vitulina) population based on aerial survey data from a 40-year period (1980-2020) is presented. The results show that the most recent harbour seal population estimate from 2020 of 10,319 (CI 95%= 6,733-13,906) seals, is 69% smaller than when systematic monitoring of the population commenced in 1980 (33,327 seals). Long term trend analysis reveals that the largest decline occurred between 1980 and 1990, when the population decreased about 50%. After that, the population decline continued, although at a slower rate. Currently, the population is considered to fluctuate around a stable minimum level. Due to the observed decline, the population is defined as endangered on the Icelandic national red list for threatened populations. The sensitive conservation status underlines that it is extremely important to map and sustainably manage threats to the population. Current research on such threats will be outlined in the presentation, including human induced removals, anthropogenic disturbance, and various environmental factors such as contaminants and potential effects of climate change. Future management implications will be discussed.